/**
 * Copyright 2009-2019 the original author or authors.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.ibatis.submitted.sqlprovider;

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.builder.annotation.ProviderContext;
import org.apache.ibatis.jdbc.SQL;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class OurSqlBuilder {

    public String buildGetUsersQuery(Map<String, Object> parameter) {
        // MyBatis wraps a single List parameter in a Map with the key="list",
        // so need to pull it out
        @SuppressWarnings("unchecked")
        List<Integer> ids = (List<Integer>) parameter.get("list");
        StringBuilder sb = new StringBuilder();
        sb.append("select * from users where id in (");
        for (int i = 0; i < ids.size(); i++) {
            if (i > 0) {
                sb.append(",");
            }
            sb.append("#{list[");
            sb.append(i);
            sb.append("]}");
        }
        sb.append(") order by id");
        return sb.toString();
    }

    public String buildGetUserQuery(Number parameter) {
        // parameter is not a single List or Array,
        // so it is passed as is from the mapper
        return "select * from users where id = #{value}";
    }

    public String buildGetAllUsersQuery() {
        return "select * from users order by id";
    }

    public String buildGetUsersByCriteriaQuery(final User criteria) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (criteria.getId() != null) {
                WHERE("id = #{id}");
            }
            if (criteria.getName() != null) {
                WHERE("name like #{name} || '%'");
            }
        }}.toString();
    }

    public String buildGetUsersByCriteriaMapQuery(final Map<String, Object> criteria) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (criteria.get("id") != null) {
                WHERE("id = #{id}");
            }
            if (criteria.get("name") != null) {
                WHERE("name like #{name} || '%'");
            }
        }}.toString();
    }

    public String buildGetUsersByCriteriaMapWithParamQuery(@Param("id") Integer id, @Param("name") String name) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (id != null) {
                WHERE("id = #{id}");
            }
            if (name != null) {
                WHERE("name like #{name} || '%'");
            }
        }}.toString();
    }

    public String buildGetUsersByNameQuery(final String name, final String orderByColumn) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (name != null) {
                WHERE("name like #{param1} || '%'");
            }
            ORDER_BY(orderByColumn);
        }}.toString();
    }

    public String buildGetUsersByNameUsingMap(Map<String, Object> params) {
        final String name = String.class.cast(params.get("param1"));
        final String orderByColumn = String.class.cast(params.get("param2"));
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (name != null) {
                WHERE("name like #{param1} || '%'");
            }
            ORDER_BY(orderByColumn);
        }}.toString();
    }

    public String buildGetUsersByNameWithParamNameAndOrderByQuery(@Param("orderByColumn") final String orderByColumn, @Param("name") final String name) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (name != null) {
                WHERE("name like #{name} || '%'");
            }
            ORDER_BY(orderByColumn);
        }}.toString();
    }

    public String buildGetUsersByNameWithParamNameQuery(@Param("name") final String name) {
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (name != null) {
                WHERE("name like #{name} || '%'");
            }
            ORDER_BY("id DESC");
        }}.toString();
    }

    public String buildGetUsersByNameWithParamNameQueryUsingMap(Map<String, Object> params) {
        final String name = String.class.cast(params.get("name"));
        final String orderByColumn = String.class.cast(params.get("orderByColumn"));
        return new SQL() {{
            SELECT("*");
            FROM("users");
            if (name != null) {
                WHERE("name like #{param1} || '%'");
            }
            ORDER_BY(orderByColumn);
        }}.toString();
    }

    public String buildInsert() {
        return "insert into users (id, name) values (#{id}, #{name})";
    }

    public String buildUpdate() {
        return "update users set name = #{name} where id = #{id}";
    }

    public String buildDelete() {
        return "delete from users where id = #{id}";
    }

    public String buildSelectByIdProviderContextOnly(ProviderContext context) {
        final boolean containsLogicalDelete = context.getMapperMethod().getAnnotation(BaseMapper.ContainsLogicalDelete.class) != null;
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        return new SQL() {{
            SELECT("*");
            FROM(tableName);
            WHERE("id = #{id}");
            if (!containsLogicalDelete) {
                WHERE("logical_delete = ${Constants.LOGICAL_DELETE_OFF}");
            }
        }}.toString();
    }

    public String buildSelectByNameOneParamAndProviderContext(ProviderContext context, final String name) {
        final boolean containsLogicalDelete = context.getMapperMethod().getAnnotation(BaseMapper.ContainsLogicalDelete.class) != null;
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        return new SQL() {{
            SELECT("*");
            FROM(tableName);
            if (name != null) {
                WHERE("name like #{name} || '%'");
            }
            if (!containsLogicalDelete) {
                WHERE("logical_delete = ${LOGICAL_DELETE_OFF:0}");
            }
        }}.toString();
    }

    public String buildSelectByIdAndNameMultipleParamAndProviderContextWithAtParam(@Param("id") final Integer id, ProviderContext context, @Param("name") final String name) {
        final boolean containsLogicalDelete = context.getMapperMethod().getAnnotation(BaseMapper.ContainsLogicalDelete.class) != null;
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        return new SQL() {{
            SELECT("*");
            FROM(tableName);
            if (id != null) {
                WHERE("id = #{id}");
            }
            if (name != null) {
                WHERE("name like #{name} || '%'");
            }
            if (!containsLogicalDelete) {
                WHERE("logical_delete = false");
            }
        }}.toString();
    }

    public String buildSelectByIdAndNameMultipleParamAndProviderContext(final Integer id, final String name, ProviderContext context) {
        final boolean containsLogicalDelete = context.getMapperMethod().getAnnotation(BaseMapper.ContainsLogicalDelete.class) != null;
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        return new SQL() {{
            SELECT("*");
            FROM(tableName);
            if (id != null) {
                WHERE("id = #{param1}");
            }
            if (name != null) {
                WHERE("name like #{param2} || '%'");
            }
            if (!containsLogicalDelete) {
                WHERE("logical_delete = false");
            }
        }}.toString();
    }

    private Class<?> getEntityClass(ProviderContext providerContext) {
        Method mapperMethod = providerContext.getMapperMethod();
        Class<?> declaringClass = mapperMethod.getDeclaringClass();
        Class<?> mapperClass = providerContext.getMapperType();

        Type[] types = mapperClass.getGenericInterfaces();
        for (Type type : types) {
            if (type instanceof ParameterizedType) {
                ParameterizedType t = (ParameterizedType) type;
                if (t.getRawType() == declaringClass || mapperClass.isAssignableFrom((Class<?>) t.getRawType())) {
                    Class<?> returnType = (Class<?>) t.getActualTypeArguments()[0];
                    return returnType;
                }
            }
        }
        throw new RuntimeException("The interface [" + mapperClass.getCanonicalName() + "] must specify a generic type.");
    }

    private Map<String, String> getColumnMap(ProviderContext context) {
        Class<?> entityClass = getEntityClass(context);
        Field[] fields = entityClass.getDeclaredFields();
        Map<String, String> columnMap = new LinkedHashMap<String, String>();
        for (Field field : fields) {
            BaseMapper.Column column = field.getAnnotation(BaseMapper.Column.class);
            if (column != null) {
                String columnName = column.value();
                if (columnName == null || columnName.length() == 0) {
                    columnName = field.getName();
                }
                columnMap.put(columnName, field.getName());
            }
        }
        if (columnMap.size() == 0) {
            throw new RuntimeException("There is no field in the class [" + entityClass.getCanonicalName()
                    + "] that specifies the @BaseMapper.Column annotation.");
        }
        return columnMap;
    }

    public String buildInsertSelective(ProviderContext context) {
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        Map<String, String> columnMap = getColumnMap(context);
        StringBuilder sqlBuffer = new StringBuilder();
        sqlBuffer.append("<script>");
        sqlBuffer.append("insert into ");
        sqlBuffer.append(tableName);
        sqlBuffer.append("<trim prefix=\"(\" suffix=\")\" suffixOverrides=\",\">");
        for (Map.Entry<String, String> entry : columnMap.entrySet()) {
            sqlBuffer.append("<if test=\"").append(entry.getValue()).append(" != null\">");
            sqlBuffer.append(entry.getKey()).append(",");
            sqlBuffer.append("</if>");
        }
        sqlBuffer.append("</trim>");
        sqlBuffer.append("<trim prefix=\"VALUES (\" suffix=\")\" suffixOverrides=\",\">");
        for (String field : columnMap.values()) {
            sqlBuffer.append("<if test=\"").append(field).append(" != null\">");
            sqlBuffer.append("#{").append(field).append("} ,");
            sqlBuffer.append("</if>");
        }
        sqlBuffer.append("</trim>");
        sqlBuffer.append("</script>");
        return sqlBuffer.toString();
    }

    public String buildUpdateSelective(ProviderContext context) {
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        Map<String, String> columnMap = getColumnMap(context);
        StringBuilder sqlBuffer = new StringBuilder();
        sqlBuffer.append("<script>");
        sqlBuffer.append("update ");
        sqlBuffer.append(tableName);
        sqlBuffer.append("<set>");
        for (Map.Entry<String, String> entry : columnMap.entrySet()) {
            sqlBuffer.append("<if test=\"").append(entry.getValue()).append(" != null\">");
            sqlBuffer.append(entry.getKey()).append(" = #{").append(entry.getValue()).append("} ,");
            sqlBuffer.append("</if>");
        }
        sqlBuffer.append("</set>");
        // For simplicity, there is no @Id annotation here, using default id directly
        sqlBuffer.append("where id = #{id}");
        sqlBuffer.append("</script>");
        return sqlBuffer.toString();
    }

    public String buildGetByEntityQuery(ProviderContext context) {
        final String tableName = context.getMapperType().getAnnotation(BaseMapper.Meta.class).tableName();
        Map<String, String> columnMap = getColumnMap(context);
        StringBuilder sqlBuffer = new StringBuilder();
        sqlBuffer.append("<script>");
        sqlBuffer.append("select * from ");
        sqlBuffer.append(tableName);
        sqlBuffer.append("<where>");
        for (Map.Entry<String, String> entry : columnMap.entrySet()) {
            sqlBuffer.append("<if test=\"").append(entry.getValue()).append(" != null\">");
            sqlBuffer.append("and ").append(entry.getKey()).append(" = #{").append(entry.getValue()).append("}");
            sqlBuffer.append("</if>");
        }
        sqlBuffer.append("</where>");
        sqlBuffer.append("</script>");
        return sqlBuffer.toString();
    }

}
